RPG QRD-734 Wood Sound Diffusors, painted dark grey. For 7 Diffusors

Downsizing system. These diffusers were professionally built and painted locally as exact copies of what RPG sells. Price is a steal as it includes 4 Units @ 2' x 81", 2 Units @ 2' x 48" and 1 Unit @ 2' x 27". They are all 9 1/4" deep. To purchase these new from RPG would cost more than 10 times asking price.
The phase grating surface of the QRD® 734 is designed to provide a more uniform sound field through mid and high frequency diffusion while the natural wood construction of the unit limits the amount of sound energy that is removed by absorption. It has become a classic shape in architectural acoustics; from its birth in 1987 it can now be found in church, theater and recording studio spaces all over the world. Its wide bandwidth, low cost, and broad selection of finishes also make it a logical choice for music education facilities, auditoriums and performing arts facilities.

Problem
Interfering reflections that degrade speech intelligibility, gain before feedback, and music quality can be controlled by absorption and/or diffusion. When absorption alone is used to control reflections it creates "dead" sounding spaces that lack the benefit of late order reflections which can greatly enhance the acoustic performance of a space.

Solution
The QRD® 734 is first and most applied sound diffusing panel in the world. Rather than remove the energy that strikes key surfaces in a space, the QRD® preserves the energy by uniformly distributing the energy back into the space. The onset of diffusion for the QRD® 734 occurs at roughly 320 Hz.

Units are marked as a "6" because they have some marks/ scratches -- nothing very noticeable at normal viewing distances and at any rate,they do come with touch up paint.
PICK UP ONLY